JP2006245849A - Communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication apparatus for detecting a network fault by its own apparatus only with high accuracy without the need for interaction using the same protocol between its own apparatus and an opposite apparatus under a multi-vendor environment. <P>SOLUTION: A tag-attached packet transmission/reception section 11 generates a tag-attached packet by attaching a tag to a packet, the tag being registered to ports of physical links L for the purpose of identifying a virtual LAN built up between its own apparatus 10 and an opposite apparatus 20, and transmits the resulting packet to the opposite apparatus 20 via one of the physical links L. Further, the tag-attached packet transmission/reception section 11 receives the tag-attached packet subjected to tunneling through the opposite apparatus 20 and transferred from the other of the physical links L. A fault detection section 12 monitors whether or not the transmitted tag-attached packet can be loop-back-received via any of the physical links L while being subjected to tunneling through the opposite apparatus 20 at both ends of the virtual link on the virtual LAN throughout of which the tag-attached packet flows so as to detect the occurrence of a fault. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a communication device, and more particularly to a communication device that detects a failure on a network.

  In recent years, there is a wide area Ethernet (Ethernet is a registered trademark) as a carrier service using a local area network (LAN) provided by a telecommunications carrier, and is now spreading. Wide-area Ethernet is a service that connects an Ethernet LAN environment using a layer 2 switch to integrate a plurality of LAN environments into one.

  Wide-area Ethernet uses inexpensive switching hubs (layer 2 switches) without using expensive routers (layer 3 switches), so costs associated with network construction and operation management can be reduced. It can be connected and expanded to the entire city area.

  In addition, in such a carrier network, if a network failure occurs and recovery is delayed, the damage will be serious. Duplication of various packages within the device, duplication of the device itself, duplication of the link, end-to-end Redundant configurations at various levels such as redundant paths are adopted, and fault tolerance is improved by promptly switching to the redundant system side when a fault is detected.

  However, no matter how many redundant configurations are provided, it is meaningless if the device itself cannot detect the failure quickly and accurately, silent failure (no automatic switching to the redundant side, and no alarm notification to the operator) If a failure that makes it difficult to recognize that an abnormal operation has occurred), the failure period lasts for a long time, and in the Ethernet network, a loop may occur and packet congestion may occur.

  12 and 13 are diagrams for explaining a network failure due to a loop. The network 50 includes nodes 51 to 54. The nodes 51 to 54 are connected to each other in a ring shape, and the node 51 and the node 54 are connected (in the drawing, the thin solid line is a physical line).

  Here, when constructing an Ethernet network, it is constructed so as to have a tree-structured path so that a loop-shaped path is not generated. This is because if there is a loop-like route on the network, packet congestion called broadcast storm occurs when the packet is broadcast.

  That is, when a broadcast packet is transmitted from a certain node, the broadcast packet is flooded from all ports other than the reception port at each node. Therefore, if there is a loop in the network, the broadcast packet Will flow indefinitely, and broadcast packets will travel through the same route.

  Then, the bandwidth is instantaneously filled with broadcast packets, and normal communication cannot be performed. For example, as shown in FIG. 12, the network 50 has a loop R (indicated by a thick solid line), so that the broadcast packet is node 51 → node 52 → node 53 → node 54 → node 51 →. , Congestion occurs due to infinite flow on the loop R.

  Therefore, when constructing an Ethernet network, it is necessary to logically cut off a loop in the layer 2 network. For example, as shown in FIG. 13, if the lines L1 and L2 are logically cut off, all loops are eliminated and the structure of the tree T is formed.

  In order to form such a tree (referred to as a spanning tree), for example, control information called BPDU (Bridge Protocol Data Unit) is exchanged between each node under the control of STP (Spanning Tree Protocol). Thus, the operation of dynamically changing the traffic route is performed (in the case of static operation, each node is set to be a tree route in advance). As a result, even in a network that physically forms a loop, it is possible to prevent a situation in which packets continue to circulate in the loop.

  However, even if a spanning tree as shown in FIG. 13 is formed, if a silent failure occurs in the network 50 and the failure detection function does not work effectively, the path recognition at each node will be different, and the tree There is a risk that the structure will collapse and a loop will occur. Therefore, in addition to providing a redundant configuration, how to detect a failure with high accuracy is an important matter for countermeasures against silent failures.

As a conventional Ethernet fault detection, a technique for executing a loopback test with a device in a LAN has been proposed (for example, Patent Document 1).
Japanese Unexamined Patent Publication No. 2003-304264 (paragraph numbers [0020] to [0027], FIG. 1)

  When a silent failure occurs as described above, the switchover from the active system to the redundant system is only due to customer complaints, and the service is interrupted for a long time. Efforts to detect are being made.

  FIG. 14 is a diagram showing a flow of network failure detection. An example of operation for detecting a general network failure by a vendor-specific protocol is shown. Nodes A and B are connected by links L30 and L40.

  [S21] The node A transmits the packet Fa to the node B through the link L30. The packet Fa has its own node identification field and another node identification field. In the node A, “A” indicating that it is the node A is inserted into the own node identification field of the packet Fa, and the other node identification field. Inserts and transmits “B” written in its own node identification column of the packet Fb received from the link L40 in a folded form.

  [S22] The node B transmits the packet Fb to the node A through the link L40. The packet Fb has an own node identification field and an other node identification field. In the node B, “B” indicating that it is the node B is inserted into the own node identification field of the packet Fb, and the other node identification field. Then, “A” written in the own node identification column of the packet Fa received from the link L30 is inserted and transmitted.

  [S23] When the node A receives the packet Fb, the node A stores the information “B” written in the own node identification column of the packet Fb in the memory (that is, stores that the partner node is B). The memory aging time (update time for clearing the memory) is 1 minute, and the transmission interval of the packet Fb is 20 seconds.

  [S24] Upon receiving the packet Fa, the node B stores the information “A” described in the own node identification column of the packet Fa in the memory (that is, the partner node is A, as in step S23). Remember that). It is assumed that the memory aging time is 1 minute and the packet Fa transmission interval is 20 seconds.

  [S25] If the packet Fb does not come three times, the node A clears the memory. At this time, the node A generates a packet Fa-1 in which “0” is inserted in the other node identification column and transmits it to the node B. Further, the node A detects that a failure has occurred in the link L40 (or the opposite node B) because the packet Fb does not come three times.

  [S26] Upon receiving the packet Fa-1, the node B recognizes that “0” is inserted in the other node identification column. That is, it recognizes that its own node identification name (B) is not transmitted to the node A and the packet Fb transmitted by itself is not normally received by the node A, and the link L40 (or the opposite node A) Detect that a failure has occurred.

  In this way, failure detection between the transmitting and receiving nodes by “not receiving a control packet from the opposite device for a certain period of time” and “the return information in the control packet received from the opposite device is different from the information transmitted by the own device” It can be performed.

  However, network failure detection using the current vendor-specific protocol is based on the premise that control is performed with the monitoring content of the opposite device in mind, as in the above example. There was a problem that only the link connected between them could be handled.

  For this reason, the current carrier network, which is becoming multi-vendor, has a problem that it is not convenient, and the standardization of a protocol for network detection failure has not progressed.

  For this reason, in a multi-vendor environment, if the opposite device can detect a network failure without being aware of failure monitoring without the mutual operation between the own device and the opposite device, it is extremely fault-tolerant. An effect in the sense of improvement is expected, and realization of such a technology is strongly desired.

  The present invention has been made in view of these points, and an object of the present invention is to provide a communication device that can detect a network failure with high accuracy only by its own device without interoperating between opposing devices using the same protocol. And

  In the present invention, in order to solve the above-described problem, a virtual LAN in which a virtual group of terminals is set independently of a physical connection form in a communication apparatus 10 that detects a failure on a network as shown in FIG. At least two physical links L that connect the opposite device 20 that has a virtual LAN setting function and does not require an interoperation for detecting a failure with the same protocol as the own device 10. And a tag for identifying a virtual LAN that is registered in the port of the physical link L and is constructed between the own device 10 and the opposite device 20 is added to the packet to generate a tagged packet. A tagged packet transmitting / receiving unit 11 that transmits to the opposite device 20, tunnels the opposite device 20, and receives a tagged packet transferred from the other physical link L; At both ends of the virtual link VL1 through which the tagged packet flows on the virtual LAN, it is monitored whether the transmitted tagged packet can be received back by tunneling through the opposing device 20 via the physical link L. There is provided a communication device 10 including a failure detection unit 12 that performs the operation.

  Here, the physical link L has a virtual LAN setting function with respect to the own device 10 having a virtual LAN setting function for setting a virtual group of terminals independently of the physical connection form. 10 is connected to the opposite device 20 which does not require the mutual operation for detecting the failure with the same protocol as the above. The tagged packet transmitting / receiving unit 11 generates a tagged packet by adding a tag for identifying a virtual LAN registered in the port of the physical link L and configured between the own device 10 and the opposite device 20 to the packet. The packet is transmitted to the opposite device 20 via one of the links L, the opposite device 20 is tunneled, and a tagged packet transferred from the other physical link L is received. The failure detection unit 12 determines whether the transmitted tagged packet is tunneled through the opposite device 20 via the physical link L at both ends of the virtual link VL1 through which the tagged packet flows on the virtual LAN. Monitor and detect faults.

  The communication device of the present invention transmits a tagged packet in which a tag for identifying a virtual LAN is attached to a packet to the opposite device via one of the physical links, and tunnels the opposite device to be transferred from the other physical link. Receive tagged packets. Then, at both ends of the virtual link through which the tagged packet flows on the physical link, monitoring is performed by monitoring whether the transmitted tagged packet can be received by tunneling through the opposite device via the physical link. The configuration. As a result, in a multi-vendor environment, it is possible to detect a network failure with high accuracy only by the own device without causing mutual operation between the own device and the opposite device using the same protocol.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a principle diagram of a communication apparatus. The communication device 10 includes a physical link L, a tagged packet transmission / reception unit 11, and a failure detection unit 12, and is a device that detects a failure on the network. The function of the communication device 10 can be applied to, for example, a layer 2 switch in a wide area Ethernet.

  Note that both the communication device 10 and the opposite device 20 have a setting function of a virtual LAN (hereinafter referred to as VLAN (Virtual LAN)). A VLAN is a LAN in which terminals connected to a network are virtually (logically) grouped independently of a physical LAN configuration, and one VLAN becomes one broadcast domain. VLAN is standardized by IEEE802.1Q (IEEE Standards for Local and Metropolitan Area Networks: Virtual Bridged Local Area Networks).

  The physical link L connects the communication device 10 and the opposite device 20 with at least two. The opposing device 20 is a device that does not require an interoperation for detecting a failure with the same protocol as the communication device 10 that is the device itself.

  For the transmission function, the tagged packet transmission / reception unit 11 adds a tag (TAG) to the packet, generates a tagged packet, and transmits the packet to one of the opposing devices 20 via one of the physical links L.

  This tag is defined by IEEE802.1Q, and the tag value is registered in the port of the physical link L and used to identify the VLAN constructed between the communication device 10 and the opposite device 20. For the reception function of the tagged packet transmitting / receiving unit 11, the opposite device 20 is tunneled and a tagged packet transferred from the other physical link L is received.

  The failure detection unit 12 tunnels the transmitted tagged packet in the opposite device 20 via the physical link L at both ends of the virtual link where the tagged packet flows on the VLAN (a closed virtual connection between the two points). A faulty connection is established by monitoring whether or not return reception is possible.

  In the figure, the communication device 10 and the opposite device 20 are connected by two physical links L1 and L2. Further, the tagged packet transmitting / receiving unit 11 transmits the tagged packet from the physical link L1, and tunnels the inside of the opposite device 20, and receives the tagged packet transferred from the physical link L2.

  The failure detection unit 12 performs failure detection by monitoring whether or not the transmitted tagged packet can be received back at both ends of the virtual link VL1 on the VLAN through which the tagged packet flows. In this case, the virtual link VL1 through which the tagged packet flows is transmitted from the port in which the tag of the set VLAN is registered in the counter device 20, so that the port receiving the tagged packet and the tag The port that transmits the attached packet is connected as if it were directly connected by a tunnel, and becomes a link unrelated to other communication methods and routes.

  Next, the basic operation of the VLAN will be described before the detailed operation of the communication device 10 is described. A device having a VLAN function is provided with a MAC (Media Access Control) table for each tag value which is a VLAN identifier.

  If a tagged packet is sent from device A to device B, device B searches the MAC table corresponding to the tag value assigned to the received packet (assuming tag value = 100).

  The device B uses the MAC table of the tag value 100 to check whether or not the destination port corresponding to the DA (Destination Address) of the received packet is written in the MAC table. If the destination port is written, it has already been learned, so a packet is output from the destination port (this destination port is naturally a port in which the tag value 100 is registered).

  Further, if the destination port is not written in the MAC table, it is not learned, and therefore, packets are flooded from all destination ports in which the tag value 100 is registered. By performing such an operation, a packet is transmitted only from a port registered with the tag value 100, and a VLAN is realized between apparatuses (communication interfaces) having a port in which the tag value 100 is registered. It will be.

  Next, the operation of the communication device 10 will be described in detail. In the following, for easy understanding, the transmission / reception function of the tagged packet transmission / reception unit 11 will be illustrated and described in two parts: a tagged packet transmission unit and a tagged packet reception unit. First, a description will be given of a first embodiment in which failure monitoring is performed with two physical links as one set.

  FIG. 2 is a diagram for explaining the operation of the first embodiment. Port # 1a of communication device 10-1 and port # 1b of opposite device 20 are connected by physical link L1, and port # 2a of communication device 10-1 and port # 2b of opposite device 20 are connected by physical link L2. The link status is monitored with the physical links L1 and L2 as one pair (ports # 1a and # 2a as one pair).

  For the opposing device 20, VLAN tags (tag value 100) to be realized between the communication device 10-1 and the opposing device 20 are registered in advance in the ports # 1b and # 2b, respectively. Further, when the packet with the tag is received at the port # 1b of the opposite device 20, it is transferred transparently from the port # 2b of the opposite device 20, and when it is received at the port # 2b of the opposite device 20, the port of the opposite device 20 is received. Set to transfer transparently from # 1b (register it statically in the MAC table of the opposing device 20. Note that this function is a normal function for devices that support IEEE802.1Q. is there).

For the failure monitoring of the flow of the port # 1a → tunneling of the opposite device 20 → port # 2a, the tagged packet transmission unit 11s-1 sends the tagged packet to which the tag value 100 is assigned from the port # 1a of the physical link L1 at a constant interval. Send with. A tagged packet having a DA (MAC DA as a multicast address) defined when transmitting from port # 1a with a tag value of 100 is referred to as a tagged packet T1 ₁₀₀ .

When receiving the tagged packet T1 ₁₀₀ , the opposite device 20 searches the MAC table corresponding to the tag value 100 for a destination port corresponding to the DA of the tagged packet T1 ₁₀₀ . Since the destination port for the corresponding DA is set as port # 2b, the tagged packet T1 ₁₀₀ is transmitted from port # 2b.

The tagged packet receiving unit 11r-2 receives the tagged packet T1 ₁₀₀ at the port # 2a of the physical link L2. The failure detection unit 12 monitors the ports # 1a and # 2a at both ends of the virtual link VL1 (monitors the tagged packet transmission unit 11s-1 and the tagged packet reception unit 11r-2), and starts from the port # 1a. It is determined whether or not the transmitted tagged packet T1 ₁₀₀ can be received back by the tunnel # 2a by tunneling the opposite device 20.

Or, for the fault monitoring of the flow of the reverse port # 2a → tunneling of the opposite device 20 → port # 1a, the tagged packet transmission unit 11s-2 sends the tagged packet with the tag value 100 (the port with the tag value 100). # a tagged packet T2 ₁₀₀ the tagged packet having a DA of determined when sent from 2a) is transmitted at regular intervals from the port # 2a physical link L2.

In the opposite apparatus 20 receives the tagged packet T2 _100, a MAC table corresponding to the tag value 100, searches the destination port corresponding to the DA of the tagged packet T2 _100. Destination port for the corresponding DA is, because it is set to the port # 1b, to send the tagged packet T2 ₁₀₀ from the port # 1b.

The tagged packet receiving unit 11r-1 receives the tagged packet T2 ₁₀₀ from the port # 1a of the physical link L1. The failure detection unit 12 monitors the ports # 1a and # 2a at both ends of the virtual link VL2 (monitors the tagged packet transmission unit 11s-2 and the tagged packet reception unit 11r-1), and starts from the port # 2a. It is determined whether or not the transmitted tagged packet T2 ₁₀₀ can tunnel and receive the opposite device 20 and return by the port # 1a.

  In the failure detection unit 12, when one or both of the virtual links VL1 and VL2 cannot receive a packet at a reception interval corresponding to a transmission interval time when a tagged packet is transmitted at a constant interval. The alarm is notified as a failure.

  As described above, the communication device 10-1 does not need to know internal processing such as table search in the opposite device 20, and the tagged packet for failure monitoring control transmitted from the port # 1a is the port # 2a or the port It is only necessary to monitor that the tagged packet for failure monitoring control transmitted from # 2a can be received at port # 1a. Further, the opposite device 20 simply outputs a tagged packet from the corresponding port in accordance with the VLAN setting operation.

  Therefore, in a multi-vendor environment, there is no need for operations such as adding a redundant port without causing the opposite device 20 side to be aware of failure monitoring without causing mutual operation between the own device and the opposite device using the same protocol. Yes, network failure can be detected efficiently.

  Here, the tagged packet will be described. The tagged packet transmission unit sets an identifier indicating that it is for failure monitoring control and the number of the transmission port when outputting from the communication device 10 as a tagged packet and outputs it.

  Whether the tagged packet is a failure monitoring control packet or a tagged packet as normal user data of a VLAN by setting an identifier for recognizing that the packet is for failure monitoring control in the tagged packet Can be identified.

  Further, in order to easily recognize from which port of the physical link the packet is transmitted within the same VLAN, the number of the transmission port of the physical link is set to the tagged packet. For example, in FIG. 2, the tagged packet transmitter 11s-1 writes # 1a as the port number in the tagged packet and outputs it from the port # 1a. When the tagged packet receiving unit 11r-2 receives the tagged packet, it can know from the number of the transmission port that this packet is output from the port # 1a (in the example of FIG. 2, one set of physical links is provided). However, it is self-evident even if the transmission port number is not set, but it is useful in a configuration in which three or more physical links are connected).

  Next, a second embodiment of the communication device 10 will be described. In the second embodiment, the failure detection control is performed when the own device and the opposite device 20 are connected by link aggregation (hereinafter referred to as LA). There are cases where a company's device and another company's device are connected by LA for link redundancy or bandwidth increase, and a case of failure detection corresponding to such a connection form will be described.

  Note that LA is a connection method in which a plurality of links are regarded as one virtual link, and is defined by IEEE.802.3ad. Hereinafter, an example in which failure detection is performed with two physical links as one LA and two LAs as one set will be described.

  FIG. 3 is a diagram for explaining the operation of the second embodiment. The communication device 10-2 and the opposite device 20 are connected by four physical links L1 to L4. The physical link L1 connects the port # 1a of the communication device 10-2 and the port # 1b of the opposite device 20, and the physical link L2 connects the port # 2a of the communication device 10-2 and the port # 2b of the opposite device 20 The physical link L3 connects the port # 3a of the communication device 10-2 and the port # 3b of the opposite device 20, and the physical link L4 connects the port # 4a of the communication device 10-2 and the port # 4b of the opposite device 20. Connect.

  Also, one physical link L1 and L2 constitute one LA (LA1), one physical link L3 and L4 constitute one LA (LA2), and LA1 and LA2 are each detected as a pair for fault detection. Do. If the LA is used to increase the bandwidth between the devices, for example, the user data flows in two branches on the two physical links L1 and L2 of LA1, and the communication device 10-2 → The data is transmitted to the opposite device 20, or the user data flows in two branches on the two physical links L3 and L4 of LA2, and is transmitted from the opposite device 20 to the communication device 10-2.

  Here, the tagged packet for fault monitoring control transmitted from the port # 1a (or port # 2a) of LA1 of the communication device 10-2 is output from the port # 3b of LA2 of the opposite device 20, or the LA2 Whether the data is output from the port # 4b is determined by the transmission port determination algorithm of the opposite device 20, and the communication device 10-2 receives the signal at either the port # 3a or the port # 4a of LA2.

  In general, when a plurality of physical links are used as one LA and packets are transmitted through the LA using this LA for bandwidth increase, a device on the packet transmission side usually has a plurality of physical links in the LA. Thus, packet transmission is performed by performing load distribution control so that the transmission amounts are the same. At this time, a hash value is obtained by performing a hash operation on the packet information to be transmitted using DA or the like in the packet header as key information (both DA and SA are used as key information for the hash operation). Or an IP address may be used), and a process for determining a destination port corresponding to the hash value is performed (or a device in which a transmission port is fixedly determined without performing such an operation) is there).

  Therefore, when the communication device 10-2 and the opposite device 20 are connected by LA, when the opposite device 20 outputs a failure monitoring control packet from the LA to the communication device 10-2, what algorithm is used to Which port is the destination port depends on the opposing device 20 (implementation dependent). Therefore, when a failure monitoring control packet is received at which port of the opposing device 20 is specified by some operation (which port of the opposing device 20 is received). From which port the failure monitoring control packet is transmitted to the communication device 10-2), the communication device 10-2 needs to recognize in advance.

  Therefore, in this example, if the tag value 100 is registered in the ports # 1b to # 4b of the opposite device 20, a tagged packet with the tag value 100 is transmitted from the port # 1a of LA1 of the communication device 10-2. In this case, the data is received by any one of the ports # 3b and # 4b of LA2, and it is necessary to recognize which port receives the data.

  As a method for identifying a port, there is a method of recognizing a reception port by using an automatic search by a program in the system. Specifically, the DA (MAC DA as a multicast address) value in the tagged packet is changed in various ways to search which DA can be received from which port and specify the port.

  For example, MAC DA as a multicast address of a tagged packet with a tag value of 100 is 01: 00: 0e: 00: 00: 01, 01: 00: 0e: 00: 00: 02, 01: 00: 0e: 00: 00 : 03, ... (note that the leading 01 represents multicast and 0e represents the manufacturer code), transmitted from port # 1a, and which DA of ports # 3a and # 4a The port can be specified by searching whether or not the tagged packet can be received.

  That is, if a tagged packet having a DA of 01: 00: 0e: 00: 00: 02 is transmitted from port # 1a and received by port # 4a, it is recognized that port # 4 is a receiving port. Yes (when the fault monitoring control packet transmitted from the port # 1a is to be received at the port # 4a (when monitoring the virtual link VL1), the DA of the fault monitoring control packet is set to 01: 00: 0e: 00: 00: 02 will be set). Alternatively, in addition to such an automatic search, the destination port may be investigated offline and a command may be specified to the communication device 10-2.

  Next, the failure monitoring of the flow of port # 1a → tunneling of the opposite device 20 → port # 4a will be described. It is assumed that the VLAN tag value 100 to be realized between the communication device 10-2 and the counter device 20 is registered in the ports # 1b to # 4b in advance in the counter device 20.

The tagged packet transmission unit 11s-1 transmits the tagged packet to which the tag value 100 is assigned from the port # 1a of the physical link L1 at regular intervals. Incidentally, the tagged packet T1 ₁₀₀ the tagged packet having a DA of determined when sent by the tag value 100 from the port # 1a.

The fact that this tagged packet T1 ₁₀₀ can be received at port # 4a has already been recognized by the above-described automatic search (in contrast, tagged packet T1 ₁₀₀ is a tagged packet with DA that can be received at port # 4a). .

Upon receiving the tagged packet T1 ₁₀₀ , the opposite device 20 performs a hash operation using the DA of the tagged packet T1 ₁₀₀ as key information, determines the port # 4a as the destination port, and the tagged packet T1 from the port # 4a. Send ₁₀₀ .

The tagged packet receiving unit 11r-4 receives the tagged packet T1 ₁₀₀ from the port # 4a of the physical link L4. The failure detection unit 12 monitors the ports # 1a and # 4a at both ends of the virtual link VL1, and can the tagged packet T1 ₁₀₀ transmitted from the port # 1a tunnel the opposite device 20 and receive it back at the port # 4a? Determine whether or not. Similarly, failure monitoring is performed for the virtual links VL2 to VL4. Since the virtual links VL2 to VL4 are the same operation as described above, the description thereof is omitted.

  In the failure detection unit 12, in the virtual links VL1 to VL4, if a packet cannot be received at a reception interval corresponding to the transmission interval time when a tagged packet is transmitted at a constant interval, it is regarded as a failure and an alarm is notified. I do.

  As described above, the communication device 10-2 does not need to know the internal processing such as the hash calculation in the opposite device 20, and can monitor the port that transmitted the tagged packet and the port that receives the return (virtual). As for the link VL1, it is only necessary to monitor that the tagged packet for failure monitoring control transmitted from the port # 1a can be received by the port # 4a (the same control is performed for the virtual links VL2 to VL4). Further, the opposite device 20 simply outputs a tagged packet from the corresponding port in accordance with the VLAN setting operation and the implemented transmission algorithm. Therefore, in a multi-vendor environment, there is no need for operations such as adding a redundant port without causing the opposite device 20 side to be aware of failure monitoring without causing mutual operation between the own device and the opposite device using the same protocol. Yes, network failure can be detected efficiently.

  Next, a third embodiment of the communication device 10 will be described. In the third embodiment, failure detection is performed using one of the three or more physical links connecting the communication device 10 and the opposite device 20 as a common physical link.

  FIG. 4 is a diagram for explaining the operation of the third embodiment. The communication device 10-3 and the opposite device 20 are connected by four physical links, one of which is a common physical link L1c and the other is a physical link group including physical links L2 to L4.

  The common physical link L1c connects the port # 1a of the communication device 10-3 and the port # 1b of the opposite device 20, and the physical link L2 connects the port # 2a of the communication device 10-3 and the port # 2b of the opposite device 20 The physical link L3 connects the port # 3a of the communication device 10-3 and the port # 3b of the opposite device 20 and the physical link L4 connects the port # 4a of the communication device 10-3 and the port # 3 of the opposite device 20. 4b is connected.

  In such a connection form, the virtual links VL1 to VL3 flowing toward the port # 1a which is the common port are monitored by the flow of the ports # 2a to # 4a → tunneling of the opposite device 20 → port # 1a. It is assumed that the tag value 100 is registered in the ports # 1b to # 4b of the opposing device 20.

The tagged packet transmission unit 11s-2 transmits the tagged packet to which the tag value 100 is assigned from the port # 2a of the physical link L2 at a constant interval. Similarly, the tagged packet transmitters 11s-3 and 11s-4 transmit the tagged packets with the tag value 100 from the ports # 3a and # 4a of the physical links L3 and L4 at regular intervals. Note that tagged packets having DA defined when transmitting from ports # 2a to # 4a with a tag value of 100 are respectively tagged packets T2 _{100 to} T4 ₁₀₀ (each DA may have the same value). Moreover, it tagged packet transmission section 11s-2~11s-4, respectively, and transmits the tagged packet T2 ₁₀₀ to T4 ₁₀₀ with a time difference.

In the opposite apparatus 20 receives the tagged packet T2 _100, a MAC table corresponding to the tag value 100, searches the destination port corresponding to the DA of the tagged packet T2 _100. Since the destination port for the corresponding DA is set to port # 1b (as described above in FIG. 2, it is statically registered in the MAC table of the opposite device 20), the tagged packet T2 ₁₀₀ is transmitted from port # 1b. Send. Also, when the tagged packets T3 ₁₀₀ and T4 ₁₀₀ are received, a similar table search is performed and transmitted from the port # 1b.

The tagged packet receiving unit 11r-1 receives the tagged packets T2 _{100 to} T4 ₁₀₀ with a time difference at the port # 1a of the common physical link L1c. The failure detection unit 12 monitors port # 1a and port # 2a, port # 1a and port # 3a, and port # 1a and port # 4a as ports at both ends of the virtual links VL1 to VL3, respectively. It is determined whether the tagged packets T2 _{100 to} T4 ₁₀₀ transmitted from # 4a tunnel the opposite device 20 and can be received back at the port # 1a.

FIG. 5 is a diagram for explaining the operation of the third embodiment. FIG. 5 shows failure monitoring of the flow of port # 1a → tunneling of the opposite device 20 → ports # 2a to # 4a.
In such a connection form, it is necessary to recognize in advance which of the ports # 2a to # 4a can receive the tagged packet transmitted from the port # 1a. Therefore, an automatic search or the like for specifying the port as described above with reference to FIG. 3 is performed. For example, a tagged packet having a tag value 100 and DA2 is received at port # 2a, and if it has DA3, port # 2 is received. Check that it can be received at 3a and can be received at port # 4a if it has DA4. Thereafter, a packet with tag value 100 can be received at the port #. 2a-# 4a respectively, and tagged packet T1a _100, T1b _100, T1c _100.

The tagged packet transmitter 11s-1 transmits the tagged packets T1a _{100 to} T1c ₁₀₀ from the port # 1a of the physical link L1c at regular intervals. In the opposite apparatus 20 receives the tagged packet T1a _100, performs a hash operation by the DA or the like of the tagged packet T1a ₁₀₀ to the key information, to determine the port # 2a as the destination port, tagged packet T1a from the port # 2a Send ₁₀₀ . Similarly, when tagged packets T1b ₁₀₀ and T1c ₁₀₀ are received, ports # 3a and # 4a are determined as destination ports, and tagged packets T1b ₁₀₀ and T1c ₁₀₀ are transmitted from ports # 3a and # 4a, respectively.

The tagged packet receiving unit 11r-2 receives the tagged packet T1a ₁₀₀ from the port # 2a of the physical link L2. Similarly, the tagged packet receiving unit 11r-3 receives the tagged packet T1b ₁₀₀ from the port # 3a of the physical link L3, and the tagged packet receiving unit 11r-4 is tagged from the port # 4a of the physical link L4. Packet T1c ₁₀₀ is received.

The failure detection unit 12 monitors the ports # 1a and # 2a at both ends of the virtual link VL4, and can the tagged packet T1a ₁₀₀ transmitted from the port # 1a tunnel the counter device 20 and receive it back at the port # 2a? Determine whether or not. Similarly, the ports # 1a and # 3a at both ends of the virtual link VL5 are monitored, and whether or not the tagged packet T1b ₁₀₀ transmitted from the port # 1a tunnels the opposite device 20 and can be received back at the port # 3a. It is determined whether or not the ports # 1a and # 4a at both ends of the virtual link VL6 are monitored, and whether or not the tagged packet T1c ₁₀₀ transmitted from the port # 1a tunnels the opposite device 20 and can be received by the port # 4a. Determine.

  In the failure detection unit 12, in the virtual links VL4 to VL6, if a packet cannot be received at a reception interval corresponding to the transmission interval time when a tagged packet is transmitted at a constant interval, it is regarded as a failure and an alarm is notified. I do.

  As described above, the communication device 10-3 does not need to know internal processing such as table search and hash calculation in the opposite device 20, and can monitor the port that transmitted the tagged packet and the port that receives the return. Good. Further, the opposite device 20 simply outputs a tagged packet from the corresponding port in accordance with the VLAN setting operation and the implemented transmission algorithm. Therefore, in a multi-vendor environment, there is no need for operations such as adding a redundant port without causing the opposite device 20 side to be aware of failure monitoring without causing mutual operation between the own device and the opposite device using the same protocol. Yes, network failure can be detected efficiently.

  In the first to third embodiments, when a failure is detected, an alarm is notified to prompt the operator to perform a maintenance operation. However, as a subsequent operation of the communication devices 10-1 to 10-3, the corresponding port is invalidated. (The opposite device 20 will detect a broken link). The disabled port is recovered manually or periodically automatically. Furthermore, it is also possible to switch to a redundant system when failure detection is switched to link redundancy / device redundancy.

  Next, the deformation | transformation operation | movement of 1st, 2nd embodiment is demonstrated. 2 and 3, the same tag value is registered in all ports of the opposite device 20, and the communication device 10-1 and 10-2 change the DA value added to the tagged packet, thereby The destination port is determined, but in the case of a deformation operation, a different tag value is registered in each port of the opposite device 20 so that the communication device has the same DA value and a different tag value. The tagged packet is transmitted / received.

  FIG. 6 is a diagram showing a failure detection operation when different tag values are registered in each port in a connection form using two physical links. The deformation | transformation operation | movement of 1st Embodiment of FIG. 2 is shown, and a connection structure is the same as that of FIG.

The tag value 100 is registered in the port # 1b and the tag value 200 is registered in the port # 2b of the opposite apparatus 20, and the MAC DA (multicast address) of the tagged packet is set to 01: 00: 0e: 00: 00: 01.
When the counter device 20 receives a tagged packet with the tag value = 100 and MAC DA = 01: 00: 0e: 00: 00: 01, it is set to transmit from the port # 1b (MAC with the tag value 100). Set port # 1b as the destination port of DA (01: 00: 0e: 00: 00: 01) in the table), tag value = 200 and MAC DA = 01: 00: 0e: 00: 00: 01 If a tagged packet is received, set to transmit from port # 2b (set port # 2b as the destination port of DA (01: 00: 0e: 00: 00: 01) in the MAC table of tag value 200) Keep it).

  The communication device 10-1a transmits a tagged packet of MAC DA = 01: 00: 0e: 00: 00: 01 with the tag value = 200 from the port # 1a, and the MAC with the tag value = 100 from the port # 2a. Send a tagged packet with DA = 01: 00: 0e: 00: 00: 01.

  Further, it is monitored whether or not a tagged packet with a tag value = 100 and MAC DA = 01: 00: 0e: 00: 00: 01 can be received by the port # 1a. When a tag value = 200, MAC DA = 01: It is monitored whether or not the packet with the tag 00: 0e: 00: 00: 01 can be received at the port # 2a.

  FIG. 7 is a diagram showing a failure detection operation when different tag values are registered in each port in a connection form using two LAs. The deformation | transformation operation | movement of 2nd Embodiment of FIG. 3 is shown, and a connection structure is the same as that of FIG. Tag values 10 to 40 are registered in the ports # 1b to # 4b of the opposite apparatus 20, and the MAC DA (multicast address) of the tagged packet is set to 01: 00: 0e: 00: 00: 01.

  When the counter device 20 receives the tagged packet with the tag value = 10 and MAC DA = 01: 00: 0e: 00: 00: 01, it transmits from the LA1 port # 1b, and the MAC value with the tag value = 20. When a tagged packet of = 01: 00: 0e: 00: 00: 01 is received, it is transmitted from port # 2b of LA1. When a tagged packet with a tag value = 30 and MAC DA = 01: 00: 0e: 00: 00: 01 is received, the packet is transmitted from port # 3b of LA2, and a tag value = 40 and MAC DA = 01: When a tagged packet of 00: 0e: 00: 00: 01 is received, it is transmitted from port # 4b of LA2.

  In the communication device 10-2a, a tagged packet with MAC DA = 01: 00: 0e: 00: 00: 01 is transmitted from the port # 1a with the tag value = 40, and the MAC with the tag value = 30 is transmitted from the port # 2a. Send a tagged packet with DA = 01: 00: 0e: 00: 00: 01, and send a tagged packet with MAC DA = 01: 00: 0e: 00: 00: 01 with tag value = 20 from port # 3a Then, a tagged packet of MAC DA = 01: 00: 0e: 00: 00: 01 with tag value = 10 is transmitted from port # 4a.

  Further, it is monitored whether or not a tagged packet with a tag value = 10 and MAC DA = 01: 00: 0e: 00: 00: 01 can be received at port # 1a of LA1, and when a tag value = 20, MAC DA = It is monitored whether the tagged packet of 01: 00: 0e: 00: 00: 01 can be received at port # 2a of LA1. Further, it is monitored whether or not the tagged packet with the tag value = 30 and MAC DA = 01: 00: 0e: 00: 00: 01 can be received by the port # 3a of LA2, and when the tag value = 40, the MAC DA = It is monitored whether the tagged packet of 01: 00: 0e: 00: 00: 01 can be received at port # 4a of LA2.

  Next, the deformation | transformation operation | movement of 3rd Embodiment is demonstrated. In FIG. 5, the same tag value is registered in all the ports of the opposite device 20, and the destination port in the opposite device 20 is determined by changing the DA value added to the tagged packet in the communication device 10-3. However, in the case of a deforming operation, a packet with a tag in which the registered tag of the port in the opposite device 20 is appropriately changed so that the communication device has the same DA value and a different registered tag value. Are sent and received.

  FIG. 8 is a diagram showing a failure detection operation when different tag values are registered in each port in a connection form having a common physical link. FIG. 7 shows a modification operation of the third embodiment of FIG. 5, and the connection configuration is the same as FIG. Tag values 20 to 40 are registered in the ports # 2b to # 4b of the opposite apparatus 20, and the MAC DA (multicast address) of the tagged packet is set to 01: 00: 0e: 00: 00: 01.

  When the counter device 20 receives a tagged packet with the tag value = 20 and MAC DA = 01: 00: 0e: 00: 00: 01, it transmits from the port # 2b, and the tag value = 30 and MAC DA = 01. : 00: 0e: 00: 00: 01 When a tagged packet is received, it is transmitted from port # 3b, tagged with a tag value = 40 and MAC DA = 01: 00: 0e: 00: 00: 01 Is transmitted from port # 4b.

  The communication device 10-3b sequentially transmits tagged packets of MAC DA = 01: 00: 0e: 00: 00: 01 having tag values = 20 to 40 respectively from the port # 1a. Then, it is monitored whether or not the tagged packet with the tag value = 20 and MAC DA = 01: 00: 0e: 00: 00: 01 can be received by the port # 2a, and the tag value = 30 and the MAC DA = 01: Monitor whether the packet with tag 00: 0e: 00: 00: 01 can be received by common port # 3a, tag value = 40 and MAC DA = 01: 00: 0e: 00: 00: 01 Whether or not the attached packet can be received by the port # 4a is monitored.

  Next, a configuration and operation when the communication device 10 is specifically realized will be described. FIG. 9 is a diagram illustrating a configuration of a communication device having the function of the communication device 10. The communication device 30 includes a device management unit 31, a CL (command line) / NMS (network management system) interface unit 32, an LCC (Link Connectivity Check) protocol processing unit 34, a filtering database processing unit 35, a line / switch control unit 36, It comprises a switching processing unit 37 and line interface processing units 38-1 to 38-n. The tagged packet transmission / reception unit 11 and the failure detection unit 12 are included in the LCC protocol processing unit 34.

  The device management unit 31 manages the entire device. Specifically, in cooperation with the provisioning information management unit 33, the switching processing unit 37, the line interface processing units 38-1 to 38-n, and the LCC protocol processing unit 34 are instructed for operating conditions based on the provisioning information of the apparatus.

  In addition, information related to the operating state / failure occurrence / failure recovery, etc. is obtained from the switching processing unit 37 / line interface processing unit 38-1 to 38-n / LCC protocol processing unit 34, and necessary actions are taken. Examples of function expansion for the device management unit 31 are shown in the following (A1) to (A4).

  (A1) The setting information of the adminstatus parameter is read for each port in cooperation with the provisioning information management unit 33, and based on this, the operating condition is instructed to the LCC protocol processing unit 34.

(A2) The failure detection is notified to the operator by the notification from the LCC protocol processing unit 34.
(A3) The failure detection is detected by the notification from the LCC protocol processing unit 34, and if necessary, the filtering database processing unit 35 is instructed to flush the filtering database.

  (A4) The failure detection is detected by the notification from the LCC protocol processing unit 34, and the line interface processing units 38-1 to 38-n transit to the Disable state via the line / switch control unit 36 if necessary. Instruct.

  The CL / NMS interface unit 32 controls an interface with CL (command line) / NMS (network management system), and here, in cooperation with the provisioning information management unit 33, sets and displays management information.

  The provisioning information management unit 33 sets / displays the provisioning information in accordance with an instruction from the CL / NMS interface unit 32, and enables the corresponding provisioning information to be referred to each functional block.

  The LCC protocol processing unit 34 is an LCC operating entity, and notifies the device management unit 31 when a failure is detected in accordance with the operation condition instructed by the device management unit 31. Examples of function expansion for the LCC protocol processing unit 34 are shown in the following (B1) to (B5).

(B1) The failure monitoring function / control packet transmission function is validated / invalidated for each port according to an instruction from the device management unit 31.
(B2) When the transmission function of the control packet (the packet with the tag for failure monitoring control) is enabled, the failure monitoring control control packet is transmitted from each port at an interval instructed by the device management unit 31 as necessary. Tell things.

(B3) When the failure monitoring function is enabled, control packet reception monitoring is performed for each port.
(B4) Upon expiration of the control packet reception monitoring timer, a failure is recognized and the device management unit 31 is notified that the corresponding port has a failure.

  (B5) In response to an instruction from the apparatus management unit 31, the line interface processing units 38-1 to 38-n are instructed to transition to the Disable state via the line / switch control unit 36.

  The filtering database processing unit 35 cooperates with the provisioning information management unit 33, the device management unit 31, and the line interface processing units 38-1 to 38-n to manage the original MAC filtering database, and to each line interface processing unit. In addition to providing a necessary MAC filtering database, the switching processing unit 37 is instructed to perform necessary switching.

  The line / switch control unit 36 notifies the operating conditions to the switching processing unit 37 / line interface processing units 38-1 to 38-n according to the instruction from the device management unit 31, and the switching processing unit 37 / line. Information about the operation state / failure occurrence / failure recovery from the interface processing units 38-1 to 38-n is notified to the device management unit 31.

The switching processing unit 37 performs switching between each line interface processing unit and necessary functional blocks in its own device in accordance with an instruction from the line / switch control unit 36.
The line interface processing units 38-1 to 38-n perform packet transmission / reception by referring to the MAC filtering database in accordance with an instruction from the line / switch control unit 36.

Next, failure detection operation settings in the communication device 30 will be described.
(1) The operation of the following items is specified independently for a single physical port.
(Item 1) A control packet provided with a specific VLAN and MAC DA (multicast address / unicast address of the opposite device) is transmitted at a specific transmission interval.

  (Item 2) The reception of a control packet to which a specific VLAN and MAC DA (multicast address / unicast address of the opposite device) are assigned is monitored, and if no packet is received for a certain period, it is determined as a failure.

(2) Control packet transmission trigger.
“The physical port of the target port is in the UP state” and “The corresponding port is specified to transmit the link connectivity check monitoring control packet”.

(3) Control packet reception monitoring trigger.
"The state in which the relevant port is designated for monitoring monitoring of the Link Connectivity Check monitoring packet" and "Receiving the control packet at the relevant port".

  When a failure is detected due to the expiration of the reception monitoring timer (failure detection TRAP (sends an alarm and prompts a maintenance operation when a failure is detected) is sent), and reception monitoring is stopped. When reception monitoring is stopped, reception monitoring is resumed when a control packet is received (TRAP for failure recovery is sent).

  Further, when the link disconnection continues for the reception monitoring timer period or longer, both the link disconnection / Link Connectivity Check failure TRAP increases, and when the link is recovered, both the link recovery / Link Connectivity Check recovery TRAP increases.

(4) Information necessary for operation of the control parameter (transmission port).
VLAN value to be assigned (including user_priority), destination MAC address, control packet transmission interval (fixed), transmission port ID (transmitted by control packet).

(5) Information necessary for the operation of the control parameter (reception monitoring port).
Assigned VLAN value (monitoring target), destination MAC address (monitoring target), reception monitoring timer (packet continuous non-reception period (fixed) determined as failure), transmission port ID (sent in control packet).

(6) Notification to maintenance personnel.
There are the following items.
(Item 1) The monitoring start is notified by TRAP (the additional information includes “transmission port”).

(Item 2) Notification of failure detected by TRAP (additional information includes “failure detection port” and “transmission port”).
(Item 3) Notification of failure recovery by TRAP (additional information includes “recovery detection port” and “transmission port”).

(Item 4) The setting state related to the Link Connectivity Check function can be referred to by a command.
(Item 5) The status of the reception monitoring port can be referred to by a command.
The port status includes “unmonitored (packet not received)”, “normal”, and “failure”, and additional information includes “transmit port (in the control packet)” and “shutdown designated port”.

  Next, the format of a tagged packet for failure monitoring control will be described. FIG. 10 is a diagram showing a format of a tagged packet for failure monitoring control. The numerical value in the figure represents byte. The explanation of each field is shown below.

  MAC DA [6] is the destination MAC address and sets the address specified by the command. 01-00-0e-00-00-01 by default. MAC SA [6] is a source MAC address, and sets the MAC address of its own device.

  TPID (Tag Protocol Identifier) [2] follows the Ether-Type setting of the port. TCI (Tag Control Information) [2] consists of user priority (3 bits), Canonical Format Indicator (1 bit) and VLAN-ID (12 bits), and user priority is set to the value specified by the command (default: 6 ), Canonical Format Indicator is fixed to 0, and VLAN-ID is set to the address specified by the command.

  L / T [2] is the Ether-Type of the fault monitoring control packet and sets the value specified by the command (default: <FF-F2>). Sub Type [1] is fixed to 0x20 (an identifier indicating a failure monitoring control packet).

  Flags [1] is fixed to 0. Code [2] is <02-00> and indicates a control packet of the LCC function. TTL (Time to Live) [1] is reserved (fixed to 255). TTL base [1] is reserved (fixed to 255).

Sequence number [2] is fixed to 0. Port-ID [2] is a port identifier of a port that transmits a packet. Padding [36] sets ALL “0”.
Next, the transmission port / reception port processing procedure and filtering conditions will be described. As for the transmission port, when the corresponding port is in the LINK UP state and the operation designation of the unidirectional link disconnection monitoring is “Transmit and Receive” or “Transmit only”, the control packet is transmitted at a specified interval.

There are the following six items for the receiving port.
(Item 1) When the port is in the LINK UP state and the unidirectional link disconnection monitoring operation specification is Transmit and Receive or Receive only, monitor that the packet is received within the specified period.

(Item 2) Monitoring is triggered by the reception of a control packet at the corresponding port. At this time, the transmission Port-ID in the packet is stored.
(Item 3) The reception monitoring timer is reset when the control packet is received.

(Item 4) Each time a packet is received, the transmission Port-ID in the packet is checked, and if there is a change, this is stored.
(Item 5) When the reception monitoring timer expires, notification to that effect is made by TRAP (additional information: detection port, transmission port).

(Item 6) Even during a failure, the reception of a packet is monitored, and a TRAP indicating that the packet has been recovered is notified when the packet is received (additional information: detection port, transmission port).
Further, the filtering condition enables reception of a control packet of a specified tag value and a specified MAC DA (multicast or own device unicast address).

  Next, the reception monitoring state machine of the communication device 30 will be described. FIG. 11 is a diagram showing the state transition of the line corresponding state machines # 1 to #n. The definition of the variable is shown below. UCT is an abbreviation for Unconditional Transition, and RESTART is a trigger at CPU switching and software version upgrade.

adminStatus: Setting status of the Link Connectivity Check function for the corresponding port. It has disabled, Txonly, Rxonly, and Tx & Rx states.
rxFrame: Indicates whether a monitoring packet has been received at that port. When receiving, true is set, and false is set when the processing for the packet is completed.

  receivedInfoWhile: This is a packet reception monitoring timer variable that sets the timer value when monitoring starts and when a packet is received. When monitoring is to be stopped, 0 is set. Note that this variable is used by a timer function for notifying that when it is not 0, it is subtracted at a cycle of 1 second and when it becomes 0 as a result.

receivePortId: Stores the transmission port ID of the packet received by this port.
sendPortId: Stores the transmission port ID in the received packet.
The function definition is shown below.

Initialize (): Performs various initializations related to the Link Connectivity Check function.
sendKeepaliveStartTrap (): Sends a trap indicating that reception monitoring of Link Connectivity Check has started.

sendFailureDetectTrap (): Sends a trap indicating that a failure has been detected by the Link Connectivity Check function.
sendNomalTrap (): Sends a trap indicating that the failure detected by the Link Connectivity Check function has been recovered.

shutdownIfConfig (): If a shutdown is specified when a failure is detected, the specified port (1 or 2) is shut down.
As described above, the communication device 10 eliminates the inconvenience that only a link connected between its own devices can detect a failure, and can detect a network failure with high accuracy even when connected to another vendor device. It becomes possible to improve fault tolerance in a multi-vendor environment. In particular, although the communication device 10 has a unique function, it does not require any changes to the devices of other companies, so that the carrier can be easily introduced in a multi-vendor environment.

(Supplementary note 1) In a communication device that detects a failure on a network,
It has the virtual LAN setting function for its own device having a virtual LAN setting function for setting a virtual group of terminals independently of the physical connection form, and can detect a failure with the same protocol as the own device. At least two physical links that connect opposite devices that do not require interoperation for
A tag is created by adding a tag for identifying the virtual LAN that is registered in the port of the physical link and is configured between the own device and the opposite device, and generates a tagged packet, via one of the physical links A tagged packet transceiver for transmitting to the opposite device, tunneling the opposite device and receiving the tagged packet transferred from the other of the physical links;
It is possible to monitor whether the tagged packet transmitted at the both ends of the virtual link through which the tagged packet flows on the virtual LAN can be received back by tunneling through the opposite device via the physical link. A fault detection unit for detection;
A communication apparatus comprising:

  (Supplementary Note 2) The tagged packet transmitting / receiving unit sets an identifier for recognizing that the packet is for failure monitoring control in the tagged packet, and which port of the physical link is in the same virtual LAN. The communication apparatus according to appendix 1, wherein a number of a transmission port of the physical link is set in the tagged packet in order to recognize whether the packet is transmitted from the network.

  (Supplementary Note 3) The tagged packet transmitting / receiving unit transmits the tagged packet from the first port of one of the physical links, and receives the tagged packet at the second port of the other physical link. Generate a first virtual link that flows from the first port to the second port, or transmit the tagged packet from the second port, and receive the tagged packet at the first port Then, a second virtual link that flows from the second port to the first port is generated, and the failure detection unit monitors the first port and the second port to monitor the first port. The communication apparatus according to appendix 1, wherein failure detection of a virtual link or the second virtual link is performed.

  (Additional remark 4) When the said own apparatus and the said opposing apparatus are connected by the link aggregation which regards the said some physical link as one virtual link, with respect to the said link aggregation used as a pair, The tagged packet transmitting / receiving unit transmits the tagged packet to the opposing device via one of the link aggregations, and tunnels the opposing device to be transferred from the other of the link aggregations. The communication apparatus according to claim 1, wherein the failure detection unit performs failure detection by monitoring both ends of a virtual link through which the tagged packet flows on the link aggregation.

  (Additional remark 5) The said tagged packet transmission / reception part transmits the said tagged packet from the 1st port with respect to each link in one said link aggregation, and each link in the said other link aggregation Receiving the tagged packet at a second port to generate a plurality of first virtual links flowing from the first port to the second port, or from the second port to the tagged packet And receiving the tagged packet at the first port to generate a plurality of second virtual links that flow from the second port to the first port, and the failure detection unit includes: Note 4 wherein the first port and the second port are monitored to detect a failure of the first virtual link or the second virtual link. Communication device.

  (Appendix 6) When one of the plurality of physical links is a common physical link for fault monitoring and the remaining physical links are physical link groups, the tagged packet transmitting / receiving unit The tagged packet is transmitted from a plurality of ports, the tagged packet is received at a common port of the common physical link, and a plurality of first virtual links flowing from the physical link group to the common physical link are generated. Or transmitting the tagged packet from the common port, receiving the tagged packet at a plurality of the ports, and generating a plurality of second virtual links that flow from the common physical link to the physical link group; The failure detection unit monitors the common port on the common physical link side and the port on the physical link group side. The communication device according to Note 1, wherein the performing detection of a failure in the first virtual link or the second virtual link.

(Supplementary note 7) In the fault detection method for detecting faults on the network,
It has the virtual LAN setting function for its own device having a virtual LAN setting function for setting a virtual group of terminals independently of the physical connection form, and can detect a failure with the same protocol as the own device. In a state where the opposing device that does not require the mutual operation for the connection is connected by at least two physical links,
Generate a tagged packet by adding a tag for identifying the virtual LAN that is registered in the port of the physical link and that is configured between the own device and the opposing device to the packet, via one of the physical links To the opposite device,
Tunneling the opposite device to receive the tagged packet forwarded from the other of the physical links;
It is possible to monitor whether the tagged packet transmitted at the both ends of the virtual link through which the tagged packet flows on the virtual LAN can be received back by tunneling through the opposite device via the physical link. A failure detection method characterized in that, by performing detection, failure detection is performed only on the own device side without recognizing failure monitoring on the opposite device side.

  (Supplementary note 8) An identifier for recognizing that the packet is for failure monitoring control is set in the tagged packet, and from which port of the physical link is the packet transmitted in the same virtual LAN The failure detection method according to appendix 7, wherein the number of the transmission port of the physical link is set in the tagged packet in order to recognize.

  (Supplementary Note 9) The tagged packet is transmitted from the first port of one of the physical links, the tagged packet is received by the second port of the other physical link, and the first packet is transmitted from the first port. Generating a first virtual link that flows to a second port, or transmitting the tagged packet from the second port, receiving the tagged packet at the first port, and A second virtual link flowing from the first port to the first port is generated, and the first port and the second port are monitored to detect a failure of the first virtual link or the second virtual link. The failure detection method according to appendix 7, wherein

  (Additional remark 10) When the said own apparatus and the said opposing apparatus are connected by the link aggregation which considers several said physical links as one virtual link, with respect to the said link aggregation used as a pair, Transmitting the tagged packet to the opposite device via one of the link aggregations, receiving the tagged packet forwarded from the other of the link aggregations by tunneling the opposite device, and the link aggregation 8. The failure detection method according to appendix 7, wherein failure detection is performed by monitoring both ends of a virtual link through which the tagged packet flows.

  (Supplementary Note 11) The tagged packet is transmitted from a first port for each link in one of the link aggregations, and the tag is transmitted at a second port for each link in the other link aggregation. A plurality of first virtual links flowing from the first port to the second port, or transmitting the tagged packet from the second port; Receiving the tagged packet at a port, generating a plurality of second virtual links flowing from the second port to the first port, and monitoring the first port and the second port; The failure detection method according to appendix 10, wherein failure detection is performed on the first virtual link or the second virtual link.

  (Supplementary Note 12) When one of the plurality of physical links is a common physical link for failure monitoring and the remaining physical links are physical link groups, the tagged packet is transmitted from a plurality of ports of the physical link group. And receiving the tagged packet at a common port of the common physical link to generate a plurality of first virtual links flowing from the physical link group to the common physical link, or from the common port to the tag A plurality of second virtual links flowing from the common physical link to the physical link group, and receiving the common packet on the common physical link side. The port and the port on the physical link group side are monitored, and the first virtual link or the second virtual link is monitored. Fault detection method according to Supplementary Note 7, wherein the performing fault detection.

It is a principle figure of a communication apparatus. It is a figure for demonstrating the operation | movement of 1st Embodiment. It is a figure for demonstrating operation | movement of 2nd Embodiment. It is a figure for demonstrating the operation | movement of 3rd Embodiment. It is a figure for demonstrating the operation | movement of 3rd Embodiment. It is a figure which shows the failure detection operation | movement at the time of registering a different tag value to each port with the connection form by two physical links. It is a figure which shows the failure detection operation | movement at the time of registering a different tag value to each port with the connection form by two LA. It is a figure which shows the failure detection operation | movement at the time of registering a different tag value to each port with the connection form which has a common physical link. It is a figure which shows the structure of the communication apparatus which has a function of a communication apparatus. It is a figure which shows the format of the packet with a tag for failure monitoring control. It is a figure which shows the state transition of a line corresponding | compatible state machine. It is a figure for demonstrating the network failure by a loop. It is a figure for demonstrating the network failure by a loop. It is a figure which shows the flow of a network failure detection.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Communication apparatus 11 Tagged packet transmission / reception part 12 Failure detection part 20 Opposite apparatus L, L1, L2 Physical link VL1 Virtual link

Claims (5)

In a communication device that detects faults on the network,
It has the virtual LAN setting function for its own device having a virtual LAN setting function for setting a virtual group of terminals independently of the physical connection form, and can detect a failure with the same protocol as the own device. At least two physical links that connect opposite devices that do not require interoperation for
A tag is created by adding a tag for identifying the virtual LAN that is registered in the port of the physical link and is configured between the own device and the opposite device, and generates a tagged packet, via one of the physical links A tagged packet transceiver for transmitting to the opposite device, tunneling the opposite device and receiving the tagged packet transferred from the other of the physical links;
It is possible to monitor whether the tagged packet transmitted at the both ends of the virtual link through which the tagged packet flows on the virtual LAN can be received back by tunneling through the opposite device via the physical link. A fault detection unit for detection;
A communication apparatus comprising:   The tagged packet transmitting / receiving unit sets an identifier for recognizing that the packet is for failure monitoring control in the tagged packet, and is transmitted from which port of the physical link in the same virtual LAN 2. The communication apparatus according to claim 1, wherein a transmission port number of the physical link is set in the tagged packet in order to recognize whether the packet is a packet.   The tagged packet transmission / reception unit transmits the tagged packet from the first port of one of the physical links, receives the tagged packet at the second port of the other physical link, and Generating a first virtual link that flows from a port of the second port to the second port, or transmitting the tagged packet from the second port, receiving the tagged packet at the first port, and A second virtual link that flows from the second port to the first port, and the failure detection unit monitors the first port and the second port to monitor the first virtual link or the second port; The communication apparatus according to claim 1, wherein failure detection of the second virtual link is performed.   When the self-device and the opposite device are connected by link aggregation in which a plurality of physical links are regarded as one virtual link, the tagged packet is used for the link aggregation to be paired. The transmitting / receiving unit transmits the tagged packet to the opposite device via one of the link aggregations, receives the tagged packet transferred from the other of the link aggregations by tunneling the opposite device, The communication apparatus according to claim 1, wherein the failure detection unit performs failure detection by monitoring both ends of a virtual link through which the tagged packet flows on the link aggregation. When one of the plurality of physical links is a common physical link for fault monitoring and the remaining physical links are physical link groups, the tagged packet transmitting / receiving unit is connected to a plurality of ports of the physical link group. Transmitting the tagged packet, receiving the tagged packet at a common port of the common physical link, generating a plurality of first virtual links flowing from the physical link group to the common physical link, or the common Transmitting the tagged packet from a port, receiving the tagged packet at a plurality of ports, generating a plurality of second virtual links flowing from the common physical link to the physical link group, and the failure detection unit Monitors the common port on the common physical link side and the port on the physical link group side, and Communication apparatus according to claim 1, characterized in that the failure detection virtual link or the second virtual link.

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